The invention relates to a guard device for machines such as bending presses, cutting machines, stamping machines or the like, wherein a first machine part performs operative movements toward a second machine part, comprising a photoelectric detector arrangement attached to the first machine part by means of a holding means and able to be repositioned in relation to the machine part, said photoelectric detector arrangement being more particularly a laser photoelectric detector arrangement, which possesses at least one photoelectric detector, whose light beam shines perpendicular to the operative movement and in an adjustable secure position is at a secure distance from such machine part in a direction toward the other machine part, and a locking means for halting operative movement on interruption of the light beam.